Modeling carbonation for corrosion risk prediction of concrete structures
Modeling carbonation for corrosion risk prediction of concrete structures
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DOI：
10.1016/s0008-8846(02)00728-7
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发表时间：
2002-06-01
影响因子：
11.4
通讯作者：
Ahrens, H
中科院分区：
文献类型：
--
作者：
Steffens, A;Dinkler, D;Ahrens, H
钢筋混凝土结构的破坏往往是由碳化引起的钢筋锈蚀引起的。尽管有关碳化作用的文献已经很多，但考虑到温度和湿度等环境影响，似乎缺乏一个全面的数值模型来定量预测腐蚀风险。本文的目的是发展一种预测混凝土结构碳化的理论模型。该模型通过平衡方程和扩散定律描述了热、水分和二氧化碳(CO2)的移动和保持。平衡方程是耦合的，并考虑了不同运输和储存过程之间的相互作用。一个新的水分平衡函数的数学公式真实地反映了多孔介质的储湿特性。由Arrhenius函数描述的反应动力学导出了CO2反应的演化方程。利用有限元概念和数值时间积分技术，采用高效的数值方法对模型进行求解。并用文献报道的前台实验结果进行了验证。考虑到大气条件的变化，研究了结构中钢筋的腐蚀风险。结合文献中的阈值，数值结果给出了钢筋混凝土结构的腐蚀风险。(C)2002爱思唯尔科学有限公司。保留所有权利。
Damage of reinforced concrete structures is often caused by corrosion of steel reinforcements due to carbonation. Although literature on carbonation has become vast, a comprehensive numerical model for quantitative prediction of the corrosion risk that allows for environmental influences such as temperature and humidity seems lacking. The aim of the present paper is the development of a theoretical model to predict carbonation of concrete structures. The model describes movement and retention of heat, moisture and carbon dioxide (CO2) by means of balance equations and diffusion laws. The balance equations are coupled and take into account the interaction between different transport and storing processes. A new mathematical formulation of the function of moisture in balance faithfully represents the moisture-storing properties of a porous media. The evolutionary equation of the reaction Of CO2 is derived from reaction kinetics that are described by the Arrhenius' function. The model is solved by means of an efficient numerical method using a Finite Element concept and numerical time integration techniques. It is verified by using results front experimental tests reported in the literature. Taking into account changing atmospheric conditions, structures are investigated with respect to the corrosion risk of steel reinforcements. Together with threshold values taken from the literature, the numerical results give the corrosion risk of reinforced concrete structures. (C) 2002 Elsevier Science Ltd. All rights reserved.